COGNITIVE PSYCHOLOGY 18, 35.5-387 (1986) Syntactic Persistence in Language Production J. KATHRYN BOCK Michigun Stn~r University Activation processes appear to have an important impact on the mechanisms of language use, including those responsible for syntactic structure in speech. Some implications of this claim for theories of language performance were examined with a syntactic priming procedure. On each priming trial, subjects produced a priming sentence in one of several syntactic forms. They then viewed an unre- lated event in a picture and described it in one sentence. The probability of a particular syntactic form being used in the description increased when that form had occurred in the prime, under presentation conditions that minimized sub- jects’ attention to their speech, to the syntactic features of the priming sentences, and to connections between the priming sentences and the subsequent pictures. This syntactic repetition effect suggests that sentence formulation processes are somewhat inertial and subject to such probabilistic factors as the frequency or recency of use of particular structural forms. Two further experiments showed that this effect was not appreciably modified by variations in certain conceptual characteristics of sentences. and all three experiments found evidence that the effects of priming were specific to features of sentence form, independent of sen- tence content. The empirical isolability of structural features from conceptual characteristics of successive utterances is consistent with the assumption thal some syntactic processes are organized into a functionally independent sub- system. 0 1986 Academic Press. Inc. The fundamental feature of the native speaker’s knowledge of language is productivity. This implies a capacity, under ideal circumstances, to generate and understand an unlimited number of different grammatical sentences in one’s language. The primary constraints on this capacity have been ascribed to a set of performance factors that customarily in- cludes memory limitations, a tendency to make mistakes, and distractibi- Experiment 1 was supported by a grant from the Alfred P. Sloan Foundation to the LJni- versity of Pennsylvania, and Experiment 2 by a faculty research grant from the Department of Psychology at Cornell University. Many people have contributed to this work, and 1 thank them all. Barbara Finlay, Jennifer Freyd, David Irwin, Frank Keil, Anthony Kroch, Joseph Stemberger, and Rose Zacks commented on earlier versions of the manuscript. Dorrit Billman, Anthony Kroch, John McKinney, Ruth Ostrin, and Eleanor Saffran offered valuable suggestions and materials for the research. Gina Cherry, Douglas Files, Paul Pe- tersen, James Yeomans, and, singularly, Constance Stillinger assisted in carrying out the experiments. Finally, W. J. M. Levelr and two anonymous reviewers helped to clarify the issues addressed in the paper. Please send correspondence, including requests for reprints, to Kathryn Bock, Department of Psychology, Psychology Research Building, Michigan State University, East Lansing, MI 48824. 355 0010-0285186 $7.50 Copyriglu 0 1986 by Academic Press, Inc. All rights of reproduction in any form reserved. 356 J. KATHRYN BOCK lity (Chomsky, 1965). This paper investigates a performance constraint of a type not directly implicated in this traditional list. The constraint is manifested in a tendency to repeatedly employ the same syntactic form across successive utterances, suggesting the existence of additional pro- cesses that are antagonistic to the productivity of syntax in actual lan- guage use. The processes in question are central to a number of current discus- sions of sentence production mechanisms (Bates & MacWhinney, 1982; Bock, 1982; Dell, 1985, in press; Harley, 1984; MacKay, 1982; Motley, Baars, & Camden, 1983; Stemberger, 1985). The common feature of these accounts is their incorporation of activation or strength constructs. In essence, the activation or strengthening of information implies a quasi-neurological energizing, excitation, or threshold reduction that per- sists over time, increasing the probability that the activated or strength- ened information will influence subsequent cognitive processes (An- derson, 1983; Posner, 1978). The intuitive evidence for activation processes in language production is most striking in everyday speech errors, which provide much of the data for current models of speech formulation. Consider mistakes such as “Get out of the Clark” (where “car” was intended, said while glancing at a store front with the name “Clark’s” printed on it; Harley, 1984), “I am a sheep in lamb’s clothing” (where “wolf’s clothing” was intended; Norman, 1981), and “If he says, ‘here’s looking at you, babe,’ take your foot out of the stirrups and wallop him in the chollops” (where “chops” was intended, Garrett, 1980). These errors suggest, respectively, the acti- vation by environmental events of information which then intruded into the utterance, the activation by one word in an utterance of a related word that displaced an intended item, and the persistence of activation of a phonological pattern from one word into a subsequent word. Although effects of activation processes in language production are most clearly documented in cases involving sounds and words, there are also subtle indications of their role in determining the syntactic features or utterances. Some of the arguments again come from speech errors. For example, mistakes such as “Do I have to put on my seatbelt on?” and “This is getting very difficult to cut this” have been interpreted as a reflection of the simultaneous activation of two different syntactic struc- tures capable of expressing the same semantic intention (Stemberger, 1982, in press). Possible influences of activation processes on syntax are also sug- gested by a pattern that has been observed in normal language use. This involves the repetition of syntactic forms across successive utterances. There have been several discussions of this and related phenomena SYNTAX IN LANGUAGE PRODUCTION 357 (Kempen, 1977; Lashley, 1951; Selz, 1922, cited by Levelt & Kelter, 1982; Schenkein, 1980), but two recent studies will serve to illustrate it. Weiner and Labov (1983) have shown that in sociolinguistic interviews, one of the factors that is significantly associated with the occurrence of a passive utterance is the presence of another passive somewhere in the previous five sentences. Levelt and Kelter (1982) also found repetition across speakers in question-answer sequences. For example, they called several hundred merchants in the Netherlands and asked them the Dutch equivalents of the questions (a) At what time does your shop close? or (b) What time does your shop close. 7. The responses to these questions varied in a very regular way: When the question contained a preposi- tional phrase, as in (a), the answer tended to be in the form of preposi- tional phrase, such as At five o’clock; when the question contained a simple noun phrase, as in (b), simple noun phrase responses such as Five o’clock increased in frequency.’ Observations such as these, which involve the structural features of utterances, raise a critical issue about the nature of the activated infor- mation. In the case of lexical and phonological intrusions, exchanges, anticipations, and related errors, it seems natural to ascribe them to the activation of mental representations of the intruding elements. Indeed, they can be elegantly explained and their relative incidence predicted by speech production models that include such activation and representa- tional assumptions (Dell, 1985, in press; Stemberger, 1985 ). In the case of syntactic intrusions or perseverations, however, it is not clear that the effects can be accounted for in a comparable way. The major problems center on differences between words and sen- tences that are related to the abstractness and discreteness of their repre- sentations. In the case of lexical knowledge, it is customary to assume that the mental representations encode such features of words as the sounds that comprise them and the order in which the sounds occur. In addition, because lexical and phonological knowledge can be represented as relatively discrete inventories of items that repeatedly enter into be- havior in much the same form, it is possible to link their mental represen- tations within networks that define similarity relationships among ele- ments in terms of shared features. Activation can then be viewed as spreading from the representation of one element in the network to the representation of another element, causing it to influence subsequent be- havior. 1 Levelt and Kelter interpreted the repetition effect they observed in terms of a tendency to reuse particular words, which in their studies were always prepositions. However, struc- tural repetition is also involved in the effect, since the repetition of the preposition required the repetition of prepositional phrase structure. 358 J. KATHRYN BOCK Neither of these assumptions holds in any clear way for the representa- tions of sentences. First, the type-to-token relationships are more com- plex than for sounds and words. In particular, it makes little sense to assume that there are permanently stored representations of sentence types that directly encode such information as the order of their compo- nent words, whether in terms of the words themselves or their form-class categories (e.g., an encoding such as “definite article, adjective, noun, past tense singular